Evacuating & Charging A/C System
About 12 years ago I bought A/C manifold gauges and an automotive refrigeration vacuum pump at Harbor Freight. I learned how to service my Cool-Pack A/C system from the Pontiac & Tempest HVAC manual and watching a couple videos.
Before charging the system a vacuum needs to be drawn to remove any moisture and air. The red hose attaches to high pressure side, blue hose to low pressure and yellow hose to vacuum pump. After the vacuum pump ran for over half an hour I shut it off. Both needles were drawn down as far as they'll go. Because I didn't have cans of r134a yet I let it sit for 4 days and the needles didn't move. There are no leaks.
After attaching a can of r134a to the yellow hose the can is punctured by the tap and air must be forced out using the valve up by gauges before charging. Refrigerant is only added to the low pressure side by opening blue knob. The cans became frosty cold as I added freon. The HVAC manual recommends placing cans in a bucket of warm water while charging.
The A/C blows cold air now although I'm not real impressed with the amount of air the fan pushes.
|